feat: add conversational RollCalc assistant

tests/test_calculation_api.py

@@ -0,0 +1,67 @@
+import base64
+import os
+import tempfile
+import unittest
+
+import app as rollcalc_app
+
+
+class CalculationApiTests(unittest.TestCase):
+    def setUp(self):
+        self.temp_dir = tempfile.TemporaryDirectory()
+        self.original_log_file = rollcalc_app.LOG_FILE
+        rollcalc_app.LOG_FILE = os.path.join(self.temp_dir.name, "access.json")
+        rollcalc_app.app.config.update(TESTING=True)
+        self.client = rollcalc_app.app.test_client()
+        credentials = base64.b64encode(b"mtazl:rollcalc").decode("ascii")
+        self.headers = {"Authorization": f"Basic {credentials}"}
+
+    def tearDown(self):
+        rollcalc_app.LOG_FILE = self.original_log_file
+        self.temp_dir.cleanup()
+
+    def test_calculation_endpoint_returns_machine_readable_authoritative_result(self):
+        response = self.client.post(
+            "/api/calculations/roll",
+            json={
+                "article_number": "180205",
+                "roll_length_m": 65,
+                "core_diameter_mm": 150,
+            },
+            headers=self.headers,
+        )
+        result = response.get_json()
+
+        self.assertEqual(response.status_code, 200)
+        self.assertEqual(result["status"], "success")
+        self.assertEqual(result["resolved_article"]["number"], "180205")
+        self.assertEqual(
+            result["provenance"]["calculator"],
+            "roll_calculation.calculate_roll",
+        )
+
+    def test_modification_endpoint_changes_state_and_recalculates(self):
+        response = self.client.post(
+            "/api/calculations/roll/modify",
+            json={
+                "state": {
+                    "request": {
+                        "article_number": "180205",
+                        "roll_length_m": 65,
+                        "core_diameter_mm": 150,
+                    }
+                },
+                "changes": {"roll_length_m": 80},
+            },
+            headers=self.headers,
+        )
+        result = response.get_json()
+
+        self.assertEqual(response.status_code, 200)
+        self.assertEqual(result["status"], "success")
+        self.assertEqual(result["state"]["request"]["roll_length_m"], 80.0)
+        self.assertEqual(result["calculation"]["effective_roll_length_m"], 80.0)
+
+
+if __name__ == "__main__":
+    unittest.main()